Matrix sensor for image touch sensing

• US 9,778,790 B2
• Filed: 06/25/2015
• Issued: 10/03/2017
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Shepelev, Petr, Ludden, Christopher A., Lukanc, Jeffrey, Morein, Stephen L., Semeraro, Greg P., Reynolds, Joseph Kurth
• Primary Examiner(s): Lam, Vinh
• Application Number:
  US14/750,735
• Publication Number:
  US 20150293643A1
• Time in Patent Office: 831 Days
• Field of Search: 345173-174
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

Embodiments described herein include an input device, a display device having a capacitive sensing device, a processing system and a method for detecting presence of an input object using a capacitive sensing device. In one embodiment, an input device includes a plurality of sensor electrodes arranged in a planar matrix array. Each sensor electrode is coupled to unique routing trace and has an identical geometric plan form that is symmetrical about a center of area of the sensor electrode. The geometric plan form of each sensor electrode includes core and a plurality of protrusions extending outward from the core. The protrusions are configured to overlap with protrusions extending outward from each adjacent sensor electrode of the matrix array.

Claims

1. A display device having an integrated capacitive sensing device, the display device comprising:

a plurality of sensor electrodes, wherein each sensor electrode of the plurality of sensor electrodes comprises at least one common electrode configured to be driven for display updating and capacitive sensing, and wherein the plurality of sensor electrodes are disposed in a matrix array of discrete sensor electrodes;

a processing system coupled to the sensor electrodes, the processing system is, during a non-display update period, configured to;

simultaneously acquire first resulting signals with each of the plurality of sensor electrodes during a first period, the first resulting signals indicative of presence of an input object;

acquire second resulting signals with a first sensor electrode of the plurality of sensor electrodes and drive a second sensor electrode of the plurality of sensor electrodes with a shielding signal during a second period;

acquire third resulting signals with the second sensor electrode during a third period, wherein the first, second and third periods are non-overlapping; and

determine first positional information for an input object based on the second and third resulting signals.

2. The input device of claim 1, wherein the processing system is further configured to drive the first sensor electrode with a shielding signal during the third period.

3. The input device of claim 1, wherein the processing system is further configured to drive the first sensor electrode with a modulated signal during the second period and wherein the shielding signal and modulated signal are similar in at least one of amplitude and phase.

4. The input device of claim 1, the processing system is further configured to determine a first capacitive image based on the first resulting signals, wherein determining the first positional information comprises determining a second capacitive image, and wherein the first capacitive image is courser than the second capacitive image.

5. The input device of claim 1, wherein the processing system is configured to move out of a low power mode in response to the first resulting signals.

6. The input device of claim 1 further comprising a grid electrode that is at least partially disposed between the first and second sensor electrodes, wherein the processing system is configured to drive the grid electrode with a transmitter signal during the first period.

7. The input device of claim 1, wherein the processing system comprises a plurality of receivers, wherein each receiver of the plurality of receivers is coupled to at least two sensor electrodes of the plurality of sensor electrodes via switching mechanism.

8. The input device of claim 1, wherein during the first period each of the plurality of sensor electrodes are held at a substantially constant voltage.

9. A processing system for a capacitive sensing device, the processing system comprising:

a sensor module comprising a sensor circuitry configured to be coupled to a plurality of sensor electrodes, wherein each of the plurality of sensor electrodes comprises at least one common electrode of a plurality of common electrodes configured for display updating and capacitive sensing, and wherein the plurality of sensor electrodes are disposed in a matrix array of discrete electrodes, the sensor module, during a non-display update period, is configured to;

simultaneously acquire first resulting signals with each of the plurality of sensor electrodes during a first period, the first resulting signals indicative of presence of an input object;

acquire second resulting signals with a first sensor electrode of the plurality of sensor electrodes and drive a second sensor electrode of the plurality of sensor electrodes with a shielding signal during a second period; and

acquire third resulting signals with the second sensor electrode during a third period, wherein the first, second and third periods are non-overlapping; and

a determination module configured to determine first positional information for an input object based on the second and third resulting signals.

10. The processing system of claim 9, wherein the sensor module is further configured to drive the first sensor electrode with a shielding signal during the second period.

11. The processing system of claim 10, wherein the sensor module is further configured to drive the first sensor electrode with a modulated signal during the second period and wherein the shielding signal and modulated signal are similar in at least one of amplitude and phase.

12. The processing system of claim 9, wherein the determination module is further configured to determine a first capacitive image based on the first resulting signal, wherein determining the first positional information comprises determining a second capacitive image, and wherein the first capacitive image is courser than the second capacitive image.

13. The processing system of claim 9, wherein the determination module is configured to move the processing system out of a low power mode in response to the first resulting signals.

14. The processing system of claim 9, wherein the processing system is coupled to a host processor and wherein the determination module is configured to move the host processor out of a low power mode in response to the first resulting signals.

15. The processing system of claim 9, wherein the processing system further comprises a display module configured to update a display.

16. The processing system of claim 15, wherein the sensor module is disposed on a first integrated circuit and the display module is disposed on a second integrated circuit and wherein the determination module is configured to move the second integrated circuit out of a low power mode in response to the first resulting signals.

17. The processing system of claim 9, wherein the sensor module is further configured to drive a grid electrode with a transmitter signal during the first period, wherein the grid electrode is at least partially disposed between the first and second sensor electrodes.

18. The processing system of claim 9, wherein the sensor module is further configured to drive a grid electrode with a shielding signal during the first period, wherein the grid electrode is at least partially disposed between the first and second sensor electrodes.

19. The processing system of claim 9, wherein the sensor module comprises a plurality of receivers, wherein each receiver of the plurality of receivers is coupled to at least two sensor electrodes of the plurality of sensor electrodes via switching mechanism.

20. The processing system of claim 9, wherein during the first period each of the plurality of sensor electrodes are held at a substantially constant voltage.

21. A method for capacitive sensing comprising:

simultaneously acquiring first resulting signals with each of a plurality of sensor electrodes during a first period of a non-display update period, the first resulting signals indicative of presence of an input object, wherein each sensor electrode of the plurality of sensor electrodes comprises at least one common electrode configured to be driven for display updating and capacitive sensing, and wherein the plurality of sensor electrodes are disposed in a matrix array of discrete sensor electrodes;

acquiring second resulting signals with a first sensor electrode of the plurality of sensor electrodes and drive a second sensor electrode of the plurality of sensor electrodes with a shielding signal during a second period of a non-display update period;

acquiring third resulting signals with the second sensor electrode during a third period of a non-display update period, wherein the first, second and third periods are non-overlapping;

driving the first sensor electrode with a shielding signal during the second period; and

determining a first capacitive image based on the first resulting signals and a second capacitive image based on the second resulting signals, wherein the first capacitive image is courser than the second capacitive image.